noun
giving cries of encouragement at a critical moment
A yojijukugo describing the act of shouting encouragement at a decisive moment, such as before a battle or competition.
試合前に監督が励声一番、選手たちを鼓舞した。
Before the match, the coach gave a rousing cry of encouragement to spur on the players.
A yojijukugo composed of 励声 (encouraging shout) and 一番 (first, best, or a single effort). The exact historical origin is uncertain.